Honeywell TH8320R

crawas

hello,

I have the above referenced thermostat and I have a one pipe steam system. when installing this thermostat, it doesn't have steam as one of the heating system options to choose from. the closest thing is radiant heat, but it doesn't seem the thermostat is working right set on radiant heat. there is a choice for "other", does anyone have this thermostat with a one pipe steam system and have it working right? it seems the boiler is shutting off always before the 2nd floor even gets remotely warm. I called Honeywell and the lady actually told me for steam that I should set it to "conventional forced air", but that sounds so wrong to me. any advice here on how to set it up correctly? its not the pressure of the boiler because I had that checked and its not the air valves of the radiators either because all the second floor radiators have gorton C valves. I ran a test where the boiler was on for 45-50 minutes continuously and the 2nd floor rads got nice and hot so when the boiler is on for the right amount of time, everything woks fine. its just that the boiler never stays on long enough when its maintaining my temp of 70 throughout the day. any help would be awesome! thanks

Tim McElwain

The steam/setback controversy...

is complicated. Steam systems have a "flywheel" effect,
which means they stay warm long after the boiler shuts down. How long depends on the building envelop,ie insulation, tyvek wrap, windows etc. Any of our new electonic stats should be set to 1 cycle per hour for steam systems. Out of the box, they are set for 6 cycles per hour, the usual setting for forced air. If your vents are working, mains are insulated, and your boiler is running right, you probably can use our FocusPro 5000 thermostat. It is NOT programmable, and it is very easy to use, has a large screen, +- 1 degree electronic accuracy, and is mercury free. Part number is TH5110D1032, and it's available from any Honeywell distributor. There is no retail equivalent.

When you get it, use your owner's manual to set it for 1 CPH, and of course, follow the mounting, wiring & installation recommendations.

Past post from Bill from Honeywell.

crawas

Thanks yes I have it set for 1cph. However there is no option for a steam system setting. It’s radiant heat or other.

ratio

I believe that the different system types, aside from any of the heat pump settings, just change certain defaults, e.g. cycles per hour; meaning that setting it to 'conventional forced air' or 'radiant heat' are operationally identical, provided you normalize the settings. This fits with the factory instructions to set the system type to 'conventional forced air' that you received earlier.

KC_Jones

And was said on the other thread you have an imbalance issue and the solution is to balance the system with proper venting. You can change the thermostat and add all the sensors you want, but in the end you will still be imbalanced and have to fix the venting.

You say the second floor isn't getting steam, if you run longer the second floor will get steam and the first floor will get hotter. So if you started with a 5 degree difference, you run the boiler you will still have a 5 degree difference, just at a higher temperature.

To get the cycles per hour (CPH) set you need to adjust setting 240 to 1. On that one I think it's in the advanced or installer menu, hopefully you have the documentation to show you how to get to those menus.

crawas

I checked the main vent that I found and it’s working fine. I spoke to a master plumber and he said the second vent could be concealed anywhere if I even have one because it’s a very old House. Who knows where it is. The radiators seem to be working a bit better these last few days as it’s been much colder. Maybe it was just a fluke. I have the therm set on radiant heat with 1 CPH

ChrisJ

> @crawas said:
> I checked the main vent that I found and it’s working fine. I spoke to a master plumber and he said the second vent could be concealed anywhere if I even have one because it’s a very old House. Who knows where it is. The radiators seem to be working a bit better these last few days as it’s been much colder. Maybe it was just a fluke. I have the therm set on radiant heat with 1 CPH



If you're the one working on the system it's your job to figure out where it is and if a main doesn't have enough venting it's your job to fix it so it does. You don't just assume it may not have one because it's old and give up.

That's my thoughts anyway. A thermostat isn't going to fix it.